A doctor who founded two beauty treatment centres had his licence removed for eight months, the heaviest penalty in recent years, for unauthorised advertisements by doctors.

The Medical Council yesterday found that the centres' advertisements from 2008 to 2010 that carried claims of "whitening" and "rejuvenating" effects from treatments were "exaggerated, misleading, or entirely false".

Dr Michael Yam Chun-hung, a founder of I-Sky Beauty and the Medical and Phototherapy Beauty Centre, was found guilty of professional misconduct in all 16 charges under four complaints.

"It was a systematic, well organised and large-scale campaign designed to bombard the public with the offending information from all directions through multiple media," said Professor Felice Lieh Mak, temporary chairman for disciplinary inquiries of the Medical Council. Yam, who was also a medical consultant at the centres and appeared in many of the adverts in question, apologised to the council and the public. "There are no excuses for my carelessness."

He said he had learned his lesson and asked the council for a chance to continue to serve patients. But the council considered him unremorseful and said his claims that he lacked knowledge about the adverts and had no control over them were false.

The advertisements appeared on the centre's websites and in leaflets, a newspaper and magazines. They involved slimming, body hair removal and skin treatments, the last of which involved a "stem-cell skin regeneration technique".

Lieh Mak called the advert for the skin treatments grossly misleading as stem cells were not involved. There is no evidence the treatment can lead to tissue regeneration and has nothing to do with rejuvenation as the centre claims.

Outside the inquiry, she said the council only acts upon complaints and called on the government to tighten regulations and enforcement over advertisements on so-called medical beauty treatments.

None of the adverts in the case mentioned the risk posed by some treatments - ones that involve blood manipulation could lead to death if infections occur.

Yam had a clear record in his past two decades as a doctor. He has dissociated himself from the centre.

This article appeared in the South China Morning Post print edition as Doctor suspended 8 months over misleading adverts